Pin-tumbler lock.



PATENTED DEC. 5,v 1905.

G. B. PICKUP. P TN TUMBLBR LOOK.- APPLIUATION FILED 1.117,1904.

"UNITED STATES l PATENT OFFICE.

GEORGE B. PICKOP, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO P. 8c F. I

CORBIN, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

PIN-TUMBLER LooK.

Patented Dec. 5, 1905.

Application led May 7, 1904. Serial No. 206,792.

To all whom t may concern.-

Beit known that I, GEORGE B. Prcxor, a citizen of the -United States,residing at New Britain, in the county of Hartford, State ofConnecticut, have invented certain new and useful Improvements inPin-Tumbler Locks, of which the following is a full, clear, and exactdescription.

My invention relates to locks, and particu' larly to a cylinder-lock`employing what is known as pin-tumblers.y

The object of my invention is to construct a lock which may bemanufactured economically, which shall be of compact form, as simple aspossible, contain as few parts as possible, and with which a broadmaster-key or an ordinary key may be employed, as desired. I have doneaway with all unnecessary parts and construct a lock which isuniversally efcient and yet adapted to uses of locks already known. Itis operable by either one of two keys of different over-all heights.

The parts of a lock embodying the improvements of my invention are shownin the accompanying single sheet of drawings.

Figure 1 is a longitudinal sectional view of those portions of azlockwhich embody the improvements of my invention. Fig. 2 is a frontelevation of the lock. Fig. 3 is a rear elevation. Fig. 4 is across-section on the plane of the line X X of Fig. l with the keywithdrawn srlid showing a slightly-different form of tumer. i

The main body 1 of the lock is usually termed the cylindelz7 This in theform shown is provided with a screw-threaded portion to the rear and aange at the front. The plug 2 is mounted in the cylinder 1 and eccentricwith relationthereto. A roll-back 3 is attached lin a suitable manner tothe rear end-of the plug and adapted for operating the latchslideorbolt, as is common in constructions of thisv general class. The key 4 isprovided for insertion in a longitudinal slot in the plug and rotatingthe plug and roll-back. The body ofv the cylinder and the plug areprovided with a series of chambers or recesses parallel to each plug andat one side of the slot forming a seat for the tumblers whenthe key iswithdrawn,

as well as a spline or guide for the key when the same. is inserted.

The tumblers are independent of each other, provided with two lines ofdivision, so that they may be operated to release the plug by either oneYof two different keys. For thisl purpose the tumblers are divided intothree parts-the driver 7 the intermediate part 8, and the lower part 9.In some cases a ball 10 is provided, forming a suitable bearing for thelower endrof the tumblers and facilitating the entrance of the key andrendering picking difficult. part 9 as integral and combining the parts9 and lO of the construction of Fig. l. The tumblers are preferably heldin their normal operating positionl by suitable springs 11, whichcontract and expand, according to the position'of the tumblers.

The tumblers are divided up transversely into parts of various sizes andby permutations and combinations afford avast variety of possiblekey-bittings. In the form herein shown a key 4 is indicated to act as amaster-key. Its insertion in the slot of the plug raises the tumblers soas to make the line of division between the lower portions 9 and theintermediate portions 8 correspond with the line between the plug andthe cylinder. The insertion of a key 4 of the form shown dotted in Fig.1 will arrange the tumblers so that the lines of division between thedrivers and the intermediate members will concur with the In Fig. 4 Ihave shown the lower line of division between the plug and the cylinder. In either case the plug may be rotated upon the insertion of theproper key. A large number of varieties of master-keys may be employedas well as a large variety of ordinary keys. It will be obvious from aninspection of the drawings that with a given form of master-key as showna large number of va- IOO In the use of the lock it will be understoodthat the key indicated by the dotted lines 4 is ordinarily theservice-key, while the key 4 is the master-key. rIhere is always asubstantial difference in the over-all height of these two keys. Forexample, the key 4 is of such a height as to only partially fill theslot in the plug 2, suiicient clearance being provided above the upperedge of the key 4' so that when the saine is withdrawn a key of greaterover-all height may be introduced. In the preferred form of course thespline 6 is provided, so that itwill hold the key 4 down in the bottomof the slot, insuring the proper positioning of the tumblers when thekey is fully inserted. Were it not for this spline 6, ofcourse thenarrower key could be raised and lowered in the slot and would not becapable of operation with that ease and certainty which the presence ofthe guide or spline 6 insures. The bittings in both of the keys may beapproximately of the same gradation-that is, the deepest bitting in themaster-key may be approximately the depth of the deepest one in theservice-key-the difference in the overall height of the larger key beingrelied upon to raise the tumbler to the higher elevation necessary tobring the second breaking-point therein coincident with thebreaking-line between the plug and the cylinder.

Heretofore master-key pin-cylinder locks have ordinarily been providedwith an intermediate shell between the plug and the cylinder. Thisconstruction involves much labor and expense.Anotherformistoprovidesplitpins or double sets of pins, which alsoinvolves added labor and expense. It will be apparent that in myinvention the expense of producing the lock is no more than in producingan ordinary pineylinder lock, and yet by reason of providing the widenedslot having a capacity for receiving a key of greater over-all height Iam able to combine with it all the advantages of a master-keycombination.

What I claim is- 1. In a master-key pin-turn bler lock, a body portion,a plug rotatably mounted directly therein and having a longitudinalkey-slot, said body and plug having a series of chambers all arranged ina single plane substantially coincident with the axis of the plug,pin-tumblers in said chambers, two or more of said tumblers beingdivided transversely into three parts, a lower operating part, an upperlocking part, and an intermediate part providing a breaking-line at eachend so that said plug may be rotated by either one of two keys ofdifferent over-all heights by arranging all of said tumblers indilferent ways, the tumblers in all of said chambers being independentof one another.

2. rlhe combination of a lock having a body portion, a plug' rotatablymounted directly therein and having a longitudinal key-slot, said bodyand plug having a series of channbers all substantiallyparallel to eachother and at right angles to the axis of the plug, pin-tumblers in saidchambers divided transversely into three parts, the tumblers in eachchamber being independent of all the other tumblers, together with twokeys with diiferent bittings, each bitting of one key being lower thanthe corresponding bitting of the other key, the difference in height ofsaid bittings being equal to the length of the intermediate parts ot'said tulnblers.

Signed at New Britain, Connecticut, this 3d day of May, 1904.

GEORGE B. PICKUP.

Vitnesses:

Gr. ERNEST Roo'r, IV. H. DE VVOLFE.

